Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Stephen Boyd <swboyd@chromium.org>]

Please update the subject. This patch does more than remove the sysfs
file. "Move loopback support to TIOCM_LOOP"?

Quoting Akash Asthana (2019-11-13 02:49:21)
> Remove code from the driver that create and maintain loopback sysfs node.
> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
> loopback mode.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
> Changes in V5:
>  - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
>    file related code.
> 
>  drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
>  1 file changed, 4 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 56dad67..52f5ea2 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>                                                         unsigned int mctrl)
>  {
>         u32 uart_manual_rfr = 0;
> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>  
>         if (uart_console(uport))
>                 return;
>  
> +       if (mctrl & TIOCM_LOOP)
> +               port->loopback = MAX_LOOPBACK_CFG;

How does this work? The loopback is supposed to be the max all the time
and not match some qup number or something?